Radio buttons input error

[GreenSpark]

Hey fellas, I recently decided to start my personal database on monsters in a game and have a website with forms etc where I can enter new monsters.

 

Now I've made a start, but I'm getting a line 15 error when trying to execute the form without having an input button ticket.

 

   

The file including the form that's related to the error (newmonster.php):

</tr><tr>
            <td>Attribute:</td>
            <td><input type="radio" name="attribute" value="dark" />Dark
            <input type="radio" name="attribute" value="earth" />Earth
            <input type="radio" name="attribute" value="fire" />Fire
            <input type="radio" name="attribute" value="light" />Light
            <input type="radio" name="attribute" value="water" />Water
            <input type="radio" name="attribute" value="wind" />Wind</td>
 

And this is the part of the file it's submitting the form to:

 

Line 15 is the line between $type and $attack. The one with $attribute declaration.

function invoer_schoonmaken($tekst)
            {
                $tekst = strip_tags($tekst);
                $tekst = htmlspecialchars($tekst);
                return $tekst;
            }
            $naam = invoer_schoonmaken($_POST["naam"]);
            $type = invoer_schoonmaken($_POST["type"]);
            $attribute = invoer_schoonmaken($_POST["attribute"]);
            $attack = invoer_schoonmaken($_POST["attack"]);
            $defense = invoer_schoonmaken($_POST["defense"]);
            $stars = invoer_schoonmaken($_POST["stars"]);
            $description = invoer_schoonmaken($_POST["description"]);
            $booster = invoer_schoonmaken($_POST["booster"]);
 

The error is gives:

 

 

So basically, what have I done wrong with the coding here?

I'm not skilled in php in any way so I'm just trying to brush it up a bit with some MySQL later, so any constructive help would be greatly appreciated.

Edited March 2, 2013 by GreenSpark

[rgopal101]

try this,

 

 $attribute = invoer_schoonmaken($_POST['attribute']);

or

 $attribute = $_POST['attribute'];

 $attribute=invoer_schoonmaken($attribute);

[GreenSpark]

Thanks, I tried both but it doesn't seem to have a better result.

The other options in the form I used <option> method and that doesn't seem to bug, maybe i'll use that instead.

Still this should also be possible I guess, so please do assist if you think you have the solution

[Jessica]

You need to check if it's set before trying to use it. isset.

[GreenSpark]

Cheers, that did the trick!

New code:

 

 

$type = invoer_schoonmaken($_POST["type"]);
$error_msg="";
            if (!isset($_POST['attribute']))
            {
                $error_msg.="<li >Geen attribute gekozen.</li>";
            }
            else
            {
            $attribute = invoer_schoonmaken($_POST['attribute']);
            }
$attack = invoer_schoonmaken($_POST["attack"]);